Method for performing reflective quality of service (qos) in wireless communication system and a device therefor

ABSTRACT

The present invention relates to a wireless communication system. More specifically, the present invention relates to a method and a device for performing reflective QoS in wireless communication system, the method comprising: receiving a DL SDAP PDU via a DL DRB with a first DRB ID from a network, wherein the DL SDAP PDU includes a first indicator indicating whether to perform updating AS mapping rule for UL and a second indicator indicating whether to perform updating NAS reflective QoS rule for UL; and performing the updating of the AS mapping rule for UL or the updating of the NAS reflective QoS rule for the UL according to the first indicator and the second indicator.

CLAIM OF PRIORITY

This application is the National Phase of PCT International ApplicationNo. PCT/KR2018/000978, filed on Jan. 23, 2018, which claims the benefitof U.S. Provisional Application No. 62/453,467, filed on Feb. 1, 2017,which are all hereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The present invention relates to a wireless communication system and,more particularly, to a method for performing reflective Quality ofService (QoS) in wireless communication system and a device therefor.

BACKGROUND ART

As an example of a mobile communication system to which the presentinvention is applicable, a 3rd Generation Partnership Project Long TermEvolution (hereinafter, referred to as LTE) communication system isdescribed in brief.

FIG. 1 is a view schematically illustrating a network structure of anE-UMTS as an exemplary radio communication system. An Evolved UniversalMobile Telecommunications System (E-UMTS) is an advanced version of aconventional Universal Mobile Telecommunications System (UMTS) and basicstandardization thereof is currently underway in the 3GPP. E-UMTS may begenerally referred to as a Long Term Evolution (LTE) system. For detailsof the technical specifications of the UMTS and E-UMTS, reference can bemade to Release 7 and Release 8 of “3rd Generation Partnership Project;Technical Specification Group Radio Access Network”.

Referring to FIG. 1, the E-UMTS includes a User Equipment (UE), eNode Bs(eNBs), and an Access Gateway (AG) which is located at an end of thenetwork (E-UTRAN) and connected to an external network. The eNBs maysimultaneously transmit multiple data streams for a broadcast service, amulticast service, and/or a unicast service.

One or more cells may exist per eNB. The cell is set to operate in oneof bandwidths such as 1.25, 2.5, 5, 10, 15, and 20 MHz and provides adownlink (DL) or uplink (UL) transmission service to a plurality of UEsin the bandwidth. Different cells may be set to provide differentbandwidths. The eNB controls data transmission or reception to and froma plurality of UEs. The eNB transmits DL scheduling information of DLdata to a corresponding UE so as to inform the UE of a time/frequencydomain in which the DL data is supposed to be transmitted, coding, adata size, and hybrid automatic repeat and request (HARQ)-relatedinformation. In addition, the eNB transmits UL scheduling information ofUL data to a corresponding UE so as to inform the UE of a time/frequencydomain which may be used by the UE, coding, a data size, andHARQ-related information. An interface for transmitting user traffic orcontrol traffic may be used between eNBs. A core network (CN) mayinclude the AG and a network node or the like for user registration ofUEs. The AG manages the mobility of a UE on a tracking area (TA) basis.One TA includes a plurality of cells.

Although wireless communication technology has been developed to LTEbased on wideband code division multiple access (WCDMA), the demands andexpectations of users and service providers are on the rise. Inaddition, considering other radio access technologies under development,new technological evolution is required to secure high competitivenessin the future. Decrease in cost per bit, increase in serviceavailability, flexible use of frequency bands, a simplified structure,an open interface, appropriate power consumption of UEs, and the likeare required.

DISCLOSURE Technical Problem

An object of the present invention devised to solve the problem lies ina method and device for performing reflective Quality of Service (QoS)in wireless communication system.

The technical problems solved by the present invention are not limitedto the above technical problems and those skilled in the art mayunderstand other technical problems from the following description.

Technical Solution

The object of the present invention can be achieved by providing amethod for User Equipment (UE) operating in a wireless communicationsystem as set forth in the appended claims.

In another aspect of the present invention, provided herein is acommunication apparatus as set forth in the appended claims.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

Advantageous Effects

In this invention, it is proposed of performing update of UL AS mappingrule and/or UL NAS mapping rule by receiving each indication forNAS-level reflective QoS activation and AS-level reflective QoSactivation.

It will be appreciated by persons skilled in the art that the effectsachieved by the present invention are not limited to what has beenparticularly described hereinabove and other advantages of the presentinvention will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention.

FIG. 1 is a diagram showing a network structure of an Evolved UniversalMobile Telecommunications System (E-UMTS) as an example of a wirelesscommunication system;

FIG. 2A is a block diagram illustrating network structure of an evolveduniversal mobile telecommunication system (E-UMTS), and FIG. 2B is ablock diagram depicting architecture of a typical E-UTRAN and a typicalEPC;

FIG. 3 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and an E-UTRAN based on a 3rd generationpartnership project (3GPP) radio access network standard;

FIG. 4A is a block diagram illustrating network structure of NG RadioAccess Network (NG-RAN) architecture, and FIG. 4B is a block diagramdepicting architecture of functional Split between NG-RAN and 5G CoreNetwork (5GC);

FIG. 5 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and a NG-RAN based on a 3rd generationpartnership project (3GPP) radio access network standard;

FIG. 6 is an example for L2 data flow between a UE and a NG-RAN;

FIG. 7 is a diagram for classification and user plane marking for QoSflows and mapping to NG-RAN resources;

FIG. 8 is a conceptual diagram for 5G QoS model;

FIG. 9 is a conceptual diagram for performing reflective Quality ofService (QoS) in wireless communication system according to embodimentsof the present invention;

FIG. 10 is an example for format of DL SDAP PDU;

FIG. 11 is an example for format of DL SDAP header;

FIGS. 12 and 13 are examples for NAS-level reflective QoS and AS-levelreflective QoS are activated according to embodiments of the presentinvention;

FIGS. 14 and 15 are examples for NAS-level reflective QoS and AS-levelreflective QoS are not activated according to embodiments of the presentinvention;

FIGS. 16 and 17 are examples for only NAS-level reflective QoS isactivated according to embodiments of the present invention; and

FIGS. 18 and 19 are examples for only AS-level reflective QoS isactivated according to embodiments of the present invention; and

FIG. 20 is a block diagram of a communication apparatus according to anembodiment of the present invention.

BEST MODE

Universal mobile telecommunications system (UMTS) is a 3rd Generation(3G) asynchronous mobile communication system operating in wideband codedivision multiple access (WCDMA) based on European systems, globalsystem for mobile communications (GSM) and general packet radio services(GPRS). The long-term evolution (LTE) of UMTS is under discussion by the3rd generation partnership project (3GPP) that standardized UMTS.

The 3GPP LTE is a technology for enabling high-speed packetcommunications. Many schemes have been proposed for the LTE objectiveincluding those that aim to reduce user and provider costs, improveservice quality, and expand and improve coverage and system capacity.The 3G LTE requires reduced cost per bit, increased serviceavailability, flexible use of a frequency band, a simple structure, anopen interface, and adequate power consumption of a terminal as anupper-level requirement.

Hereinafter, structures, operations, and other features of the presentinvention will be readily understood from the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings. Embodiments described later are examples in which technicalfeatures of the present invention are applied to a 3GPP system.

Although the embodiments of the present invention are described using along term evolution (LTE) system and a LTE-advanced (LTE-A) system inthe present specification, they are purely exemplary. Therefore, theembodiments of the present invention are applicable to any othercommunication system corresponding to the above definition. In addition,although the embodiments of the present invention are described based ona frequency division duplex (FDD) scheme in the present specification,the embodiments of the present invention may be easily modified andapplied to a half-duplex FDD (H-FDD) scheme or a time division duplex(TDD) scheme.

FIG. 2A is a block diagram illustrating network structure of an evolveduniversal mobile telecommunication system (E-UMTS). The E-UMTS may bealso referred to as an LTE system. The communication network is widelydeployed to provide a variety of communication services such as voice(VoIP) through IMS and packet data.

As illustrated in FIG. 2A, the E-UMTS network includes an evolved UMTSterrestrial radio access network (E-UTRAN), an Evolved Packet Core (EPC)and one or more user equipment. The E-UTRAN may include one or moreevolved NodeB (eNodeB) 20, and a plurality of user equipment (UE) 10 maybe located in one cell. One or more E-UTRAN mobility management entity(MME)/system architecture evolution (SAE) gateways 30 may be positionedat the end of the network and connected to an external network.

As used herein, “downlink” refers to communication from eNodeB 20 to UE10, and “uplink” refers to communication from the UE to an eNodeB. UE 10refers to communication equipment carried by a user and may be alsoreferred to as a mobile station (MS), a user terminal (UT), a subscriberstation (SS) or a wireless device.

FIG. 2B is a block diagram depicting architecture of a typical E-UTRANand a typical EPC.

As illustrated in FIG. 2B, an eNodeB 20 provides end points of a userplane and a control plane to the UE 10. MME/SAE gateway 30 provides anend point of a session and mobility management function for UE 10. TheeNodeB and MME/SAE gateway may be connected via an S1 interface.

The eNodeB 20 is generally a fixed station that communicates with a UE10, and may also be referred to as a base station (BS) or an accesspoint. One eNodeB 20 may be deployed per cell. An interface fortransmitting user traffic or control traffic may be used between eNodeBs20.

The MME provides various functions including NAS signaling to eNodeBs20, NAS signaling security, AS Security control, Inter CN node signalingfor mobility between 3GPP access networks, Idle mode UE Reachability(including control and execution of paging retransmission), TrackingArea list management (for UE in idle and active mode), PDN GW andServing GW selection, MME selection for handovers with MME change, SGSNselection for handovers to 2G or 3G 3GPP access networks, Roaming,Authentication, Bearer management functions including dedicated bearerestablishment, Support for PWS (which includes ETWS and CMAS) messagetransmission. The SAE gateway host provides assorted functions includingPer-user based packet filtering (by e.g. deep packet inspection), LawfulInterception, UE IP address allocation, Transport level packet markingin the downlink, UL and DL service level charging, gating and rateenforcement, DL rate enforcement based on APN-AMBR. For clarity MME/SAEgateway 30 will be referred to herein simply as a “gateway,” but it isunderstood that this entity includes both an MME and an SAE gateway.

A plurality of nodes may be connected between eNodeB 20 and gateway 30via the S1 interface. The eNodeBs 20 may be connected to each other viaan X2 interface and neighboring eNodeBs may have a meshed networkstructure that has the X2 interface.

As illustrated, eNodeB 20 may perform functions of selection for gateway30, routing toward the gateway during a Radio Resource Control (RRC)activation, scheduling and transmitting of paging messages, schedulingand transmitting of Broadcast Channel (BCCH) information, dynamicallocation of resources to UEs 10 in both uplink and downlink,configuration and provisioning of eNodeB measurements, radio bearercontrol, radio admission control (RAC), and connection mobility controlin LTE ACTIVE state. In the EPC, and as noted above, gateway 30 mayperform functions of paging origination, LTE-IDLE state management,ciphering of the user plane, System Architecture Evolution (SAE) bearercontrol, and ciphering and integrity protection of Non-Access Stratum(NAS) signaling.

The EPC includes a mobility management entity (MME), a serving-gateway(S-GW), and a packet data network-gateway (PDN-GW). The MME hasinformation about connections and capabilities of UEs, mainly for use inmanaging the mobility of the UEs. The S-GW is a gateway having theE-UTRAN as an end point, and the PDN-GW is a gateway having a packetdata network (PDN) as an end point.

FIG. 3 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and an E-UTRAN based on a 3GPP radioaccess network standard. The control plane refers to a path used fortransmitting control messages used for managing a call between the UEand the E-UTRAN. The user plane refers to a path used for transmittingdata generated in an application layer, e.g., voice data or Internetpacket data.

A physical (PHY) layer of a first layer provides an information transferservice to a higher layer using a physical channel. The PHY layer isconnected to a medium access control (MAC) layer located on the higherlayer via a transport channel. Data is transported between the MAC layerand the PHY layer via the transport channel. Data is transported betweena physical layer of a transmitting side and a physical layer of areceiving side via physical channels. The physical channels use time andfrequency as radio resources. In detail, the physical channel ismodulated using an orthogonal frequency division multiple access (OFDMA)scheme in downlink and is modulated using a single carrier frequencydivision multiple access (SC-FDMA) scheme in uplink.

The MAC layer of a second layer provides a service to a radio linkcontrol (RLC) layer of a higher layer via a logical channel. The RLClayer of the second layer supports reliable data transmission. Afunction of the RLC layer may be implemented by a functional block ofthe MAC layer. A packet data convergence protocol (PDCP) layer of thesecond layer performs a header compression function to reduceunnecessary control information for efficient transmission of anInternet protocol (IP) packet such as an IP version 4 (IPv4) packet oran IP version 6 (IPv6) packet in a radio interface having a relativelysmall bandwidth.

A radio resource control (RRC) layer located at the bottom of a thirdlayer is defined only in the control plane. The RRC layer controlslogical channels, transport channels, and physical channels in relationto configuration, re-configuration, and release of radio bearers (RBs).An RB refers to a service that the second layer provides for datatransmission between the UE and the E-UTRAN. To this end, the RRC layerof the UE and the RRC layer of the E-UTRAN exchange RRC messages witheach other.

One cell of the eNB is set to operate in one of bandwidths such as 1.25,2.5, 5, 10, 15, and 20 MHz and provides a downlink or uplinktransmission service to a plurality of UEs in the bandwidth. Differentcells may be set to provide different bandwidths.

Downlink transport channels for transmission of data from the E-UTRAN tothe UE include a broadcast channel (BCH) for transmission of systeminformation, a paging channel (PCH) for transmission of paging messages,and a downlink shared channel (SCH) for transmission of user traffic orcontrol messages. Traffic or control messages of a downlink multicast orbroadcast service may be transmitted through the downlink SCH and mayalso be transmitted through a separate downlink multicast channel (MCH).

Uplink transport channels for transmission of data from the UE to theE-UTRAN include a random access channel (RACH) for transmission ofinitial control messages and an uplink SCH for transmission of usertraffic or control messages. Logical channels that are defined above thetransport channels and mapped to the transport channels include abroadcast control channel (BCCH), a paging control channel (PCCH), acommon control channel (CCCH), a multicast control channel (MCCH), and amulticast traffic channel (MTCH).

FIG. 4A is a block diagram illustrating network structure of NG RadioAccess Network (NG-RAN) architecture, and FIG. 4B is a block diagramdepicting architecture of functional Split between NG-RAN and 5G CoreNetwork (5GC).

An NG-RAN node is a gNB, providing NR user plane and control planeprotocol terminations towards the UE, or an ng-eNB, providing E-UTRAuser plane and control plane protocol terminations towards the UE.

The gNBs and ng-eNBs are interconnected with each other by means of theXn interface. The gNBs and ng-eNBs are also connected by means of the NGinterfaces to the 5GC, more specifically to the AMF (Access and MobilityManagement Function) by means of the NG-C interface and to the UPF (UserPlane Function) by means of the NG-U interface.

The Xn Interface includes Xn user plane (Xn-U), and Xn control plane(Xn-C). The Xn User plane (Xn-U) interface is defined between two NG-RANnodes. The transport network layer is built on IP transport and GTP-U isused on top of UDP/IP to carry the user plane PDUs. Xn-U providesnon-guaranteed delivery of user plane PDUs and supports the followingfunctions: i) Data forwarding, and ii) Flow control. The Xn controlplane interface (Xn-C) is defined between two NG-RAN nodes. Thetransport network layer is built on SCTP on top of IP. The applicationlayer signalling protocol is referred to as XnAP (Xn ApplicationProtocol). The SCTP layer provides the guaranteed delivery ofapplication layer messages. In the transport IP layer point-to-pointtransmission is used to deliver the signalling PDUs. The Xn-C interfacesupports the following functions: i) Xn interface management, ii) UEmobility management, including context transfer and RAN paging, and iii)Dual connectivity.

The NG Interface includes NG User Plane (NG-U) and NG Control Plane(NG-C). The NG user plane interface (NG-U) is defined between the NG-RANnode and the UPF. The transport network layer is built on IP transportand GTP-U is used on top of UDP/IP to carry the user plane PDUs betweenthe NG-RAN node and the UPF. NG-U provides non-guaranteed delivery ofuser plane PDUs between the NG-RAN node and the UPF.

The NG control plane interface (NG-C) is defined between the NG-RAN nodeand the AMF. The transport network layer is built on IP transport. Forthe reliable transport of signalling messages, SCTP is added on top ofIP. The application layer signalling protocol is referred to as NGAP (NGApplication Protocol). The SCTP layer provides guaranteed delivery ofapplication layer messages. In the transport, IP layer point-to-pointtransmission is used to deliver the signalling PDUs.

NG-C provides the following functions: i) NG interface management, ii)UE context management, iii) UE mobility management, iv) ConfigurationTransfer, and v) Warning Message Transmission.

The gNB and ng-eNB host the following functions: i) Functions for RadioResource Management: Radio Bearer Control, Radio Admission Control,Connection Mobility Control, Dynamic allocation of resources to UEs inboth uplink and downlink (scheduling), ii) IP header compression,encryption and integrity protection of data, iii) Selection of an AMF atUE attachment when no routing to an AMF can be determined from theinformation provided by the UE, iv) Routing of User Plane data towardsUPF(s), v) Routing of Control Plane information towards AMF, vi)Connection setup and release, vii) Scheduling and transmission of pagingmessages (originated from the AMF), viii) Scheduling and transmission ofsystem broadcast information (originated from the AMF or O&M), ix)Measurement and measurement reporting configuration for mobility andscheduling, x) Transport level packet marking in the uplink, xi) SessionManagement, xii) Support of Network Slicing, and xiii) QoS Flowmanagement and mapping to data radio bearers. The Access and MobilityManagement Function (AMF) hosts the following main functions: i) NASsignalling termination, ii) NAS signalling security, iii) AS Securitycontrol, iv) Inter CN node signalling for mobility between 3GPP accessnetworks, v) Idle mode UE Reachability (including control and executionof paging retransmission), vi) Registration Area management, vii)Support of intra-system and inter-system mobility, viii) AccessAuthentication, ix) Mobility management control (subscription andpolicies), x) Support of Network Slicing, and xi) SMF selection.

The User Plane Function (UPF) hosts the following main functions: i)Anchor point for Intra-/Inter-RAT mobility (when applicable), ii)External PDU session point of interconnect to Data Network, iii) Packetinspection and User plane part of Policy rule enforcement, iv) Trafficusage reporting, v) Uplink classifier to support routing traffic flowsto a data network, vi) QoS handling for user plane, e.g. packetfiltering, gating, UL/DL rate enforcement, and vii) Uplink Trafficverification (SDF to QoS flow mapping).

The Session Management function (SMF) hosts the following mainfunctions: i) Session Management, ii) UE IP address allocation andmanagement, iii) Selection and control of UP function, iv) Configurestraffic steering at UPF to route traffic to proper destination, v)Control part of policy enforcement and QoS, vi) Downlink DataNotification.

FIG. 5 is a diagram showing a control plane and a user plane of a radiointerface protocol between a UE and a NG-RAN based on a 3rd generationpartnership project (3GPP) radio access network standard.

The user plane protocol stack contains Phy, MAC, RLC, PDCP and SDAP(Service Data Adaptation Protocol) which is newly introduced to support5G QoS model.

The main services and functions of SDAP entity include i) Mappingbetween a QoS flow and a data radio bearer, and ii) Marking QoS flow ID(QFI) in both DL and UL packets. A single protocol entity of SDAP isconfigured for each individual PDU session.

At the reception of an SDAP SDU from upper layer for a QoS flow, thetransmitting SDAP entity may map the SDAP SDU to the default DRB ifthere is no stored QoS flow to DRB mapping rule for the QoS flow. Ifthere is a stored QoS flow to DRB mapping rule for the QoS flow, theSDAP entity may map the SDAP SDU to the DRB according to the stored QoSflow to DRB mapping rule. And the SDAP entity may construct the SDAP PDUand deliver the constructed SDAP PDU to the lower layers.

FIG. 6 is an example for L2 data flow between a UE and a NG-RAN.

An example of the Layer 2 Data Flow is depicted on FIG. 6, where atransport block is generated by MAC by concatenating two RLC PDUs fromRBx and one RLC PDU from RBy. The two RLC PDUs from RBx each correspondsto one IP packet (n and n+1) while the RLC PDU from RBy is a segment ofan IP packet (m).

FIG. 7 is a diagram for classification and user plane marking for QoSflows and mapping to NG-RAN resources.

The 5G QoS model is based on QoS flows. The 5G QoS model supports bothQoS flows that require guaranteed flow bit rate (GBR QoS flows) and QoSflows that do not require guaranteed flow bit rate (non-GBR QoS flows).The 5G QoS model also supports reflective QoS.

The QoS flow is the finest granularity of QoS differentiation in the PDUsession. A QoS Flow ID (QFI) is used to identify a QoS flow in the 5GSystem. User plane traffic with the same QFI within a PDU Sessionreceives the same traffic forwarding treatment (e.g. scheduling,admission threshold). The QFI is carried in an encapsulation header onN3 (and N9) i.e. without any changes to the e2e packet header. QFI shallbe used for all PDU session types. The QFI shall be unique within a PDUsession. The QFI may be dynamically assigned or may be equal to the 5QI.

Within the 5G System, a QoS flow is controlled by the SMF and may bepreconfigured, or established via the PDU Session Establishmentprocedure, or the PDU Session Modification procedures.

Any QoS flow is characterized by: i) a QoS profile provided by the SMFto the NG-RAN via the AMF over the N2 reference point or preconfiguredin the NG-RAN, ii) one or more QoS rule(s) which can be provided by theSMF to the UE via the AMF over the N1 reference point and/or derived bythe UE by applying reflective QoS control, and iii) one or more SDFtemplates provided by the SMF to the UPF.

The UE performs the classification and marking of UL user plane traffic,i.e. the association of UL traffic to QoS flows, based on QoS rules.These QoS rules may be explicitly provided to the UE (using the PDUSession Establishment/Modification procedure), pre-configured in the UEor implicitly derived by UE by applying reflective QoS.

Reflective QoS enables the UE to map UL user plane traffic to QoS flowsby creating UE derived QoS rules in the UE based on the received DLtraffic.

A QoS rule contains a QoS rule identifier which is unique within the PDUsession, the QFI of the associated QoS flow and a packet filter set forUL and optionally for DL and a precedence value. Additionally, for adynamically assigned QFI, the QoS rule contains the QoS parametersrelevant to the UE (e.g. 5QI, GBR and MBR and the Averaging Window).There can be more than one QoS rule associated with the same QoS Flow(i.e. with the same QFI)

A default QoS rule is required for every PDU Session and associated withthe QoS flow of the default QoS rule. The principle for classificationand marking of user plane traffic and mapping of QoS flows to NG-RANresources is illustrated in FIG. 7.

In DL, incoming data packets are classified by the UPF based on SDFtemplates according to their SDF precedence, (without initiatingadditional N4 signaling). The UPF conveys the classification of the userplane traffic belonging to a QoS flow through an N3 (and N9) user planemarking using a QFI. The NG-RAN binds QoS flows to NG-RAN resources(i.e. Data Radio Bearers). There is no strict 1:1 relation between QoSflows and NG-RAN resources. It is up to the NG-RAN to establish thenecessary NG-RAN resources that QoS flows can be mapped to.

In UL, the UE evaluates UL packets against the packet filter set in theQoS rules based on the precedence value of QoS rules in increasing orderuntil a matching QoS rule (i.e. whose packet filter matches the ULpacket) is found. The UE uses the QFI in the corresponding matching QoSrule to bind the UL packet to a QoS flow.

FIG. 8 is a conceptual diagram for 5G QoS model.

As shown in the FIG. 8, multiple user plane traffics (e.g, IP flow) canbe multiplexed onto the same QoS flow and multiple QoS flows can bemultiplexed onto the same DRB (Data Radio Bearer). In DL, 5GC isresponsible for the IP flow to QoS flow mapping and NG-RAN isresponsible for the QoS flow to DRB mapping. In UL, the UE performs a2-step mapping of IP flows, in which NAS is responsible for the IP flowto QoS flow mapping, and AS is responsible for the QoS flow to DRBmapping. In other words, the UE maps an IP flow to a QoS flow accordingto the QoS rules such as default QoS rule, pre-authorised QoS ruleand/or reflective QoS rule which 5GC provides to the UE. And then, theUE maps the QoS flow to a DRB according to the AS mapping rules whichthe NG-RAN provides to the UE.

If the IP flow is not matched to any of QoS rule(s) in the UE, the UEcan't map the IP flow to a QoS flow and thus can't transmit UL packet ofthe IP flow to network since the IP flow doesn't belong to any QoSflows. For handling this case, the UE can trigger a NAS procedure torequest to get an appropriate QoS rule. However, it introducesadditional delays since the UE has to wait for the responsecorresponding to the request. The problem becomes severe for urgent ULpacket which needs to be transmitted immediately.

This invention relates to a method and apparatus for performing ULpacket transmission of IP flow which is not matched to any of QoSrule(s) in the UE.

FIG. 9 is a conceptual diagram for performing reflective Quality ofService (QoS) in wireless communication system according to embodimentsof the present invention.

Some terms of this invention are defined as the followings:

-   -   PDU session refers to association between the UE and a data        network that provides a PDU connectivity service.    -   PDU connectivity service refers to a service that provides        exchange of PDU (Packet Data Units) between a UE and a data        network.    -   QoS rule refers to a set of information enabling the detection        of a service data flow (e.g., IP flow) and defining its        associated QoS parameters. It consists of NAS-level QoS profile        (e.g., QoS characteristics, QoS marking) and packet filters.        Three types of QoS rule are Default QoS Rule, Pre-authorised QoS        rule and Reflective QoS rule.    -   Default QoS rule refers to a mandatory QoS rule per PDU session.        It is provided at PDU Session Establishment to UE.    -   Pre-authorised QoS rule refers to any QoS rule (different from        the Default QoS rule) provided at PDU Session Establishment.    -   Reflective QoS rule refers to the QoS rule which is created by        UE based on QoS rule applied on the DL traffic.    -   QoS marking refers to a scalar that is used as a reference to a        specific packet forwarding behaviour    -   Packet filter refers to information for matching service data        flows. The format of the packet filters is a pattern for        matching the IP 5 tuple (source IP address or IPv6 network        prefix, destination IP address or IPv6 network prefix, source        port number, destination port number, protocol ID of the        protocol above IP). Service data flows are mapped to a QoS flow        according to DL/UL packet filter.    -   QoS flow refers to finest granularity for QoS treatment.    -   NG (Next Generation) system consists of AMF (Access and Mobility        Management Function), SMF (Session Management Function) and UPF        (User plane Function).    -   AS mapping rule refers to a set of information related to the        association between QoS flow and the Data Radio Bearer (DRB)        transporting that QoS flow.    -   AS-level reflective QoS refers to updating the UL AS mapping        rule in the UE based on the DL packet with QoS flow ID received        within a DRB.    -   PDU refers to Packet Data Unit.    -   SDU refers to Service Data Unit.    -   Service Data Adaptation Protocol (SDAP) refers to a user plane        AS protocol layer for the 5G QoS model.

During the PDU Session Establishment (S901), UE receives QoS rule(s)related to the PDU session from 5GC, and receives AS mapping rule(s) andDRB configuration information for the PDU session from NG-RAN.

The UL packet filter(s) of QoS rule(s) related to the PDU session is aUL IP flow (i.e. user plane traffic) to QoS flow mapping rule configuredto the UE.

The AS-mapping rule(s) is a UL QoS flow to DRB mapping rule configuredto the UE.

The UE saves the received QoS rule(s) and AS-mapping rule(s), andestablishes DRB such as default DRB and/or Dedicated DRB (non-defaultDRB).

The default DRB is established by NG-RAN at PDU Session Establishment.If the first packet of the flow is UL packet, if no mapping rule isconfigured in the UE, the packet is sent through default DRB to thenetwork.

After that, the UE receives a DL SDAP data PDU from NG-RAN via a DL DRBwith a first DRB ID (S903).

Preferably, the DL SDAP PDU is a PDU for a SDAP entity which is a higherlayer than a PDCP entity of the UE.

Preferably, the DL SDAP PDU includes an AS-level Reflective QoSactivation indication indicating whether to perform updating of theAccess Stratum (AS) mapping rule in the UE for uplink (UL) and aNAS-level Reflective QoS activation indication indicating whether toperform updating of the Non Access Stratum (NAS) reflective QoS rule forUL.

Preferably, if at least one of the NAS-level reflective QoS activationindication or the AS-level reflective QoS activation indication is setto ‘1’, the DL SDAP PDU further includes a QoS flow ID.

If the AS-level reflective QoS activation indication is set to ‘1’, theUE updates UL AS mapping rule. When the UE updates UL AS mapping rule, aUL DRB mapped to a UL QoS flow with the first QoS flow ID is set to a ULDRB with the first DRB ID (S905). If the AS-level reflective QoSactivation indication is set to ‘0’, the UE does not update UL ASmapping rule (S907).

If the NAS-level reflective QoS activation indication is set to ‘1’, theQoS flow ID in the received DL SDAP data PDU is delivered with theretrieved DL SDAP data SDU from the DL SDAP data PDU to upper layer inthe UE. When a QoS flow ID with DL traffic is received from lower layer,the UE updates UL QoS rule. When the UE updates UL QoS rule, a UL QoSflow mapped to a UL IP flow with a first IP flow ID of the DL traffic isset to a UL QoS flow with the first QoS flow ID (S909).

If the NAS-level reflective QoS activation indication is set to ‘0’,only the retrieved DL SDAP data SDU is delivered to upper layer in theUE. When only DL traffic is received from lower layer, the UE does notupdate UL QoS rule (S911).

If both NAS-level Reflective QoS activation indication and AS-levelReflective QoS activation indication are ‘0’, the UE recognizes that theDL SDAP data PDU consists of NAS-level reflective QoS activationindication and AS-level reflective QoS activation indication, excludingthe QoS flow ID.

When a UL packet with a first IP flow is received from an upper layer,the UE marks QFI of the first QoS flow, which is mapped to the first IPflow, in the UL packet, if updating of the NAS reflective QoS rule forUL is performed by the NAS-level reflective QoS activation indicationbeing set to 1 (S913), and transmits the UL packet via a first DRB,which is mapped to the first QoS flow ID, to the network, if updating ofthe AS mapping rule for UL is performed by the AS-level reflective QoSactivation indication being set to 1 (S915).

FIG. 10 is an example for format of DL SDAP data PDU, and FIG. 11 is anexample for format of DL SDAP header.

The DL SDAP data PDU consists of a DL Data field and a DL SDAP header.The DL SDAP header can be appended in front of the DL Data (format 1) orat the end of the DL Data (format 2), as shown in the FIG. 10.

As shown in the FIG. 11, the DL SDAP header consists of NAS-levelreflective QoS activation indication, AS-level reflective QoS activationindication and QoS flow ID (format 1). NAS-level reflective QoSactivation indication and AS-level reflective QoS activation indicationare present for every DL SDAP header. In order to decrease protocoloverhead, QoS flow ID can be present for DL SDAP header only when it isnecessary depending on the values of two reflective QoS activationindications. So, if both NAS-level Reflective QoS activation indicationand AS-level Reflective QoS activation indication are ‘0’, the DL SDAPheader may not include the QoS flow ID (format 2).

FIG. 12 is an example for NAS-level reflective QoS and AS-levelreflective QoS are activated according to embodiments of the presentinvention.

During the PDU Session Establishment, 5GC transmits QoS rule(s) relatedto the PDU session to the UE and transmits QoS rule(s) excluding packetfilter to the NG-RAN. The NG-RAN sends the UE the RRC message fordefault DRB establishment of the corresponding PDU session. The RRCmessage includes some configurations such as AS-mapping rule. The NG-RANreceives RRC message from UE as response to the RRC message.

During the PDU Session Establishment, UE receives QoS rule(s) related tothe PDU session from 5GC, and receives AS-mapping rule(s) and defaultDRB configuration information for the PDU session from NG-RAN. And theUE saves the received QoS rule(s) and AS-mapping rule(s), andestablishes default DRB. After that, the UE may update QoS rules byreceiving NAS message including QoS rules or by receiving DL packetindicating the Reflective QoS activation (S1201).

When 5GC decides to activate NAS-level reflective QoS, DL data with QoSmarking and reflective QoS activation indication is transmitted toNG-RAN (S1203). QoS marking and reflective QoS activation indication arecarried in encapsulation header on NG-U i.e. without any changes to thee2e packet header

If the reflective QoS activation indication in the receivedencapsulation header is ‘1’, the NG-RAN sets NAS-level Reflective QoSactivation indication of DL SDAP header to ‘1’ (S1205).

If the NG-RAN decides to activate AS-level reflective QoS, the NG-RANsets AS-level Reflective QoS activation indication of DL SDAP header to‘1’. (S1207)

The NG-RAN maps the QoS flow of the DL packet to a DRB defined by the ASmapping rules, and then transmits DL SDAP data PDU to the UE via the DRB(S1209).

In this case, the DL SDAP data PDU includes AS level reflective QoSactivation indication and NAS level reflective QoS activation indicationand a QoS flow ID.

If the AS-level reflective QoS activation indication and NAS-levelreflective QoS activation indication are set to ‘1’, the UE updates ULAS mapping rule, delivers the received QoS flow ID and DL data to upperlayer in the UE and updates UL QoS rule (S1211).

FIG. 13 shows an example for the Steps of S1211.

When receiving a DL SDAP data PDU including QoS flow ID=13 via a DL DRB2, the UE checks AS-level reflective QoS activation indication andNAS-level reflective QoS activation indication.

If AS-level reflective QoS activation indication and NAS-levelreflective QoS activation indication are set to ‘1’, the UE sets a ULDRB mapped to the QoS flow ID=13 to a UL DRB 2 (=updating AS mappingrule), and sets a UL QoS flow mapped to a IP flow ID=yyy to a UL QoSflow ID=13 (=updating NAS reflective QoS rule).

FIG. 14 is an example for NAS-level reflective QoS and AS-levelreflective QoS are not activated according to embodiments of the presentinvention.

During the PDU Session Establishment, 5GC transmits QoS rule(s) relatedto the PDU session to the UE and transmits QoS rule(s) excluding packetfilter to the NG-RAN. The NG-RAN sends the UE the RRC message fordefault DRB establishment of the corresponding PDU session. The RRCmessage includes some configurations such as AS-mapping rule. The NG-RANreceives RRC message from UE as response to the RRC message.

During the PDU Session Establishment, UE receives QoS rule(s) related tothe PDU session from 5GC, and receives AS-mapping rule(s) and defaultDRB configuration information for the PDU session from NG-RAN. And theUE saves the received QoS rule(s) and AS-mapping rule(s), andestablishes default DRB. After that, the UE may update QoS rules byreceiving NAS message including QoS rules or by receiving DL packetindicating the Reflective QoS activation (S1401).

When 5GC decides not to activate NAS-level reflective QoS, DL data withQoS marking and reflective QoS activation indication is transmitted toNG-RAN (S1403). QoS marking and reflective QoS activation indication arecarried in encapsulation header on NG-U i.e. without any changes to thee2e packet header

If the reflective QoS activation indication in the receivedencapsulation header is ‘0’, the NG-RAN sets NAS-level Reflective QoSactivation indication of DL SDAP header to ‘0’ (S1405).

If the NG-RAN decides not to activate AS-level reflective QoS, theNG-RAN sets AS-level Reflective QoS activation indication of DL SDAPheader to ‘0’ (S1407)

The NG-RAN maps the QoS flow of the DL packet to a DRB defined by the ASmapping rules, and then transmits DL SDAP data PDU to the UE via the DRB(S1409).

In this case, the DL SDAP data PDU includes AS level reflective QoSactivation indication and NAS level reflective QoS activation indicationwithout QoS flow ID.

If the AS-level reflective QoS activation indication and NAS-levelreflective QoS activation indication are set to ‘0’, the UE doesn'tupdate UL AS mapping rule, delivers the received DL data to upper layerin the UE and doesn't update UL QoS rule (S1411).

FIG. 15 shows an example for the Steps of S1411.

When receiving a DL SDAP data PDU via a DL DRB 2, the UE checks AS-levelreflective QoS activation indication and NAS-level reflective QoSactivation indication.

If AS-level reflective QoS activation indication and NAS-levelreflective QoS activation indication are set to ‘0’, the UL AS mappingrule and UL QoS rule are not changed at all.

FIG. 16 is an example for only NAS-level reflective QoS is activatedaccording to embodiments of the present invention.

During the PDU Session Establishment, 5GC transmits QoS rule(s) relatedto the PDU session to the UE and transmits QoS rule(s) excluding packetfilter to the NG-RAN. The NG-RAN sends the UE the RRC message fordefault DRB establishment of the corresponding PDU session. The RRCmessage includes some configurations such as AS-mapping rule. The NG-RANreceives RRC message from UE as response to the RRC message.

During the PDU Session Establishment, UE receives QoS rule(s) related tothe PDU session from 5GC, and receives AS-mapping rule(s) and defaultDRB configuration information for the PDU session from NG-RAN. And theUE saves the received QoS rule(s) and AS-mapping rule(s), andestablishes default DRB. After that, the UE may update QoS rules byreceiving NAS message including QoS rules or by receiving DL packetindicating the Reflective QoS activation (S1601).

When 5GC decides to activate NAS-level reflective QoS, DL data with QoSmarking and reflective QoS activation indication is transmitted toNG-RAN (S1603). QoS marking and reflective QoS activation indication arecarried in encapsulation header on NG-U i.e. without any changes to thee2e packet header

If the reflective QoS activation indication in the receivedencapsulation header is ‘1’, the NG-RAN sets NAS-level Reflective QoSactivation indication of DL SDAP header to ‘1’ (S1605).

If the NG-RAN decides not to activate AS-level reflective QoS, theNG-RAN sets AS-level Reflective QoS activation indication of DL SDAPheader to ‘0’. (S1607)

The NG-RAN maps the QoS flow of the DL packet to a DRB defined by the ASmapping rules, and then transmits DL SDAP data PDU to the UE via the DRB(S1609).

In this case, the DL SDAP data PDU includes AS level reflective QoSactivation indication and NAS level reflective QoS activation indicationand QoS flow ID.

If the AS-level reflective QoS activation indication is set to ‘0’ andNAS-level reflective QoS activation indication is set to ‘1’, the UEdoesn't update UL AS mapping rule, delivers the received QoS flow ID andDL data to upper layer in the UE and updates UL QoS rule (S1611).

FIG. 17 shows an example for the Steps of S1611.

When receiving a DL SDAP data PDU including QoS flow ID=13 via a DL DRB3, the UE checks AS-level reflective QoS activation indication andNAS-level reflective QoS activation indication.

If the AS-level reflective QoS activation indication is set to ‘0’ andNAS-level reflective QoS activation indication is set to ‘1’, the UEsets a UL QoS flow mapped to a IP flow ID=yyy to a UL QoS flow ID=13(=updating NAS reflective QoS rule), and UL AS mapping rule doesn'tchange at all.

FIG. 18 is an example for only AS-level reflective QoS is activatedaccording to embodiments of the present invention.

During the PDU Session Establishment, 5GC transmits QoS rule(s) relatedto the PDU session to the UE and transmits QoS rule(s) excluding packetfilter to the NG-RAN. The NG-RAN sends the UE the RRC message fordefault DRB establishment of the corresponding PDU session. The RRCmessage includes some configurations such as AS-mapping rule. The NG-RANreceives RRC message from UE as response to the RRC message.

During the PDU Session Establishment, UE receives QoS rule(s) related tothe PDU session from 5GC, and receives AS-mapping rule(s) and defaultDRB configuration information for the PDU session from NG-RAN. And theUE saves the received QoS rule(s) and AS-mapping rule(s), andestablishes default DRB. After that, the UE may update QoS rules byreceiving NAS message including QoS rules or by receiving DL packetindicating the Reflective QoS activation (S1801).

When 5GC decides not to activate NAS-level reflective QoS, DL data withQoS marking and reflective QoS activation indication is transmitted toNG-RAN (S1803). QoS marking and reflective QoS activation indication arecarried in encapsulation header on NG-U i.e. without any changes to thee2e packet header

If the reflective QoS activation indication in the receivedencapsulation header is ‘0’, the NG-RAN sets NAS-level Reflective QoSactivation indication of DL SDAP header to ‘0’ (S1805).

If the NG-RAN decides to activate AS-level reflective QoS, the NG-RANsets AS-level Reflective QoS activation indication of DL SDAP header to‘1’. (S1807)

The NG-RAN maps the QoS flow of the DL packet to a DRB defined by the ASmapping rules, and then transmits DL SDAP data PDU to the UE via the DRB(S1809).

In this case, the DL SDAP data PDU includes AS level reflective QoSactivation indication and NAS level reflective QoS activation indicationand QoS flow ID.

If the AS-level reflective QoS activation indication is set to ‘1’ andNAS-level reflective QoS activation indication is set to ‘0’, the UEupdates UL AS mapping rule, delivers DL data to upper layer in the UEand doesn't update UL QoS rule (S1811).

FIG. 19 shows an example for the Steps of S1811.

When receiving a DL SDAP data PDU including QoS flow ID=13 via a DL DRB2, the UE checks AS-level reflective QoS activation indication andNAS-level reflective QoS activation indication.

If the AS-level reflective QoS activation indication is set to ‘1’ andNAS-level reflective QoS activation indication is set to ‘0’, the UEsets a UL DRB mapped to the QoS flow ID=13 to a UL DRB 2 (=updating ASmapping rule), and QoS rule doesn't change at all.

FIG. 20 is a block diagram of a communication apparatus according to anembodiment of the present invention.

The apparatus shown in FIG. 20 can be a user equipment (UE) and/or eNBadapted to perform the above mechanism, but it can be any apparatus forperforming the same operation.

As shown in FIG. 20, the apparatus may comprises a DSP/microprocessor(110) and RF module (transceiver; 135). The DSP/microprocessor (110) iselectrically connected with the transceiver (135) and controls it. Theapparatus may further include power management module (105), battery(155), display (115), keypad (120), SIM card (125), memory device (130),speaker (145) and input device (150), based on its implementation anddesigner's choice.

Specifically, FIG. 20 may represent a UE comprising a receiver (135)configured to receive a request message from a network, and atransmitter (135) configured to transmit the transmission or receptiontiming information to the network. These receiver and the transmittercan constitute the transceiver (135). The UE further comprises aprocessor (110) connected to the transceiver (135: receiver andtransmitter).

Also, FIG. 20 may represent a network apparatus comprising a transmitter(135) configured to transmit a request message to a UE and a receiver(135) configured to receive the transmission or reception timinginformation from the UE. These transmitter and receiver may constitutethe transceiver (135). The network further comprises a processor (110)connected to the transmitter and the receiver. This processor (110) maybe configured to calculate latency based on the transmission orreception timing information.

The embodiments of the present invention described hereinbelow arecombinations of elements and features of the present invention. Theelements or features may be considered selective unless otherwisementioned. Each element or feature may be practiced without beingcombined with other elements or features. Further, an embodiment of thepresent invention may be constructed by combining parts of the elementsand/or features. Operation orders described in embodiments of thepresent invention may be rearranged. Some constructions of any oneembodiment may be included in another embodiment and may be replacedwith corresponding constructions of another embodiment. It is obvious tothose skilled in the art that claims that are not explicitly cited ineach other in the appended claims may be presented in combination as anembodiment of the present invention or included as a new claim bysubsequent amendment after the application is filed.

In the embodiments of the present invention, a specific operationdescribed as performed by the BS may be performed by an upper node ofthe BS. Namely, it is apparent that, in a network comprised of aplurality of network nodes including a BS, various operations performedfor communication with an MS may be performed by the BS, or networknodes other than the BS. The term ‘eNB’ may be replaced with the term‘fixed station’, ‘Node B’, ‘Base Station (BS)’, ‘access point’, etc.

The above-described embodiments may be implemented by various means, forexample, by hardware, firmware, software, or a combination thereof.

In a hardware configuration, the method according to the embodiments ofthe present invention may be implemented by one or more ApplicationSpecific Integrated Circuits (ASICs), Digital Signal Processors (DSPs),Digital Signal Processing Devices (DSPDs), Programmable Logic Devices(PLDs), Field Programmable Gate Arrays (FPGAs), processors, controllers,microcontrollers, or microprocessors.

In a firmware or software configuration, the method according to theembodiments of the present invention may be implemented in the form ofmodules, procedures, functions, etc. performing the above-describedfunctions or operations. Software code may be stored in a memory unitand executed by a processor. The memory unit may be located at theinterior or exterior of the processor and may transmit and receive datato and from the processor via various known means.

Those skilled in the art will appreciate that the present invention maybe carried out in other specific ways than those set forth hereinwithout departing from essential characteristics of the presentinvention. The above embodiments are therefore to be construed in allaspects as illustrative and not restrictive. The scope of the inventionshould be determined by the appended claims, not by the abovedescription, and all changes coming within the meaning of the appendedclaims are intended to be embraced therein.

INDUSTRIAL APPLICABILITY

While the above-described method has been described centering on anexample applied to the 3GPP LTE system, the present invention isapplicable to a variety of wireless communication systems in addition tothe 3GPP LTE system.

1. A method for a user equipment (UE) operating in a wirelesscommunication system, the method comprising: receiving a downlink (DL)Service Data Adaptation Protocol (SDAP) Protocol Data Unit (PDU) via aDL Data Radio Bearer (DRB), wherein the DL SDAP PDU includes a DL SDAPheader being appended in front of DL Data, wherein the DL SDAP headerincludes a Quality of service Flow Identification (QFI), a firstindication related to a Quality of Service (QoS) flow for an AccessStratum (AS) level, and a second indication related to a QoS flow for aNon Access Stratum (NAS) level; storing, by a SDAP entity, a reflectiveQoS flow to DRB mapping rule for UL based on the QFI when the firstindication is set to ‘1’, and mapping, by the SDAP entity, an UL SDAPPDU to an UL DRB based on the stored reflective QoS flow to DRB mappingrule for UL; and informing, by the SDAP entity, the QFI to a NAS layerwhen the second indication is set to ‘1’.
 2. The method according toclaim 1, wherein when at least one of the first indication or the secondindication is set to ‘1’, the DL SDAP PDU includes the QFI.
 3. Themethod according to claim 1, wherein when both of the first indicationand the second indication are set to ‘0’, the DL SDAP PDU does notinclude the QFI.
 4. The method according to claim 1, wherein when thefirst indication is set to ‘0’, the reflective QoS to DRB mapping rulefor UL is not stored.
 5. The method according to claim 1, wherein whenthe second indication is set to ‘0’, the QFI is not informed to the NASlayer.
 6. (canceled)
 7. The method according to claim 1, wherein the DLSDAP PDU and the UL SDAP PDU are PDUs for the SDAP entity which is ahigher layer than a Packet Data Convergence Protocol (PDCP) entity ofthe UE.
 8. The method according to claim 1, further comprising: markinga QoS flow of the QFI in the UL packet received from an upper layer whenthe QFI is informed to the NAS layer based on the second indicationbeing set to 1, transmitting the mapped UL SDAP PDU via the UL DRB basedon the stored reflective QoS flow to DRB mapping rule for UL when thereflective QoS flow to DRB mapping rule for UL is stored based on thefirst indication being set to
 1. 9. A User Equipment (UE) for operatingin a wireless communication system, the UE comprising: a Radio Frequency(RF) module; and a processor operably coupled with the RF module andconfigured to: receive a downlink (DL) Service Data Adaptation Protocol(SDAP) Protocol Data Unit (PDU) via a DL Data Radio Bearer (DRB),wherein the DL SDAP PDU includes a DL SDAP header being appended infront of DL Data, wherein the DL SDAP header includes a Quality ofservice Flow Identification (QFI), a first indication related to aQuality of Service (QoS) flow for an Access Stratum (AS) level, and asecond indication related to a QoS flow for a Non Access Stratum (NAS)level; store, by a SDAP entity, a reflective QoS flow to DRB mappingrule for UL based on the QFI when the first indication is set to ‘1’,and map, by the SDAP entity, an UL SDAP PDU to an UL DRB based on thestored reflective QoS flow to DRB mapping rule for UL; and inform, bythe SDAP entity, the QFI is informed to a NAS layer when the secondindication is set to ‘1’.
 10. The UE according to claim 9, wherein whenat least one of the first indication or the second indication is set to‘1’, the DL SDAP PDU includes the QFI.
 11. The UE according to claim 9,wherein when both of the first indication and the second indication areset to ‘0’, the DL SDAP PDU does not include the QFI.
 12. The UEaccording to claim 9, wherein when the first indication is set to ‘0’,the reflective QoS flow to DRB mapping rule for UL is not stored. 13.The UE according to claim 9, wherein when the second indication is setto ‘0’, the QFI is not informed to the NAS layer.
 14. The UE accordingto claim 9, wherein the first indication and the second indication areincluded in a header of a DL Service Data Adaptation Protocol (SDAP)Protocol Data Unit (PDU).
 15. The UE according to claim 9, wherein theDL SDAP PDU and the UL SDAP PDU are PDUs for the SDAP entity which is ahigher layer than a Packet Data Convergence Protocol (PDCP) entity ofthe UE.
 16. The UE according to claim 9, wherein the processor isfurther configured to: mark a QoS flow of the QFI, in the UL packetreceived from an upper layer when the QFI is informed to the NAS layerbased on the second indication being set to 1, transmit the mapped ULSDAP PDU via the UL DRB based on the stored reflective QoS flow to DRBmapping rule for UL when the reflective QoS flow to DRB mapping rule forUL is stored based on the first indication being set to 1.